Various devices and methods have been used in association with minimally-invasive surgical procedures. Examples of minimally-invasive surgical procedures include stabilization techniques for stabilizing bony structures such as long bones and the spinal column. The fracture of an elongated bone, such as a femur or humerus, can be stabilized by securing a plate to the fractured bone across the fracture. The plate extends across the fractured area and stabilizes the fractured components of the bones relative to one another in a desired position. When the fracture heals, the plate can be removed or left in place, depending on the type of plate that is used. Another type of stabilization technique uses one or more elongated rods extending between components of a bony structure, such as the vertebrae of the spinal column, and secured to the bony structure to stabilize the components relative to one another. The components of the bony structure are exposed, and one or more bone engaging elements are anchored to each component. The elongated rod is then secured to the bone engaging elements in order to stabilize the components of the bony structure.
One problem associated with the above described stabilization techniques is that the skin and tissue surrounding the surgical site must be cut, removed and/or repositioned in order for the surgeon to access the location where the device is to be inserted. This repositioning of tissue causes trauma, damage and/or scarring to the tissue. There are also risks that the tissue will become infected, or that longer recovery times will be required after surgery for the tissue to heal.
Minimally-invasive surgical techniques are particularly desirable in, for example, spinal, vascular, and neurosurgical applications because of the need for access to locations deep within the body and the presence of vital intervening tissues. The development of percutaneous, minimally-invasive procedures has yielded a major improvement in reducing recovery time and post-operative pain because they require minimal, if any, muscle dissection, and can also be performed under local anesthesia. The benefits of minimally-invasive techniques have also found application in surgeries adjacent other locations in the body where it is desirable to minimize tissue disruption and/or trauma. Current techniques for inserting implants and instrumentation utilize X-ray, fluoroscopic and/or magnetic resonance imaging to provide bi-planar visualization of the target location and of the implanted objects. However, these techniques can present difficulties for the surgeon in interpreting the relative three-dimensional location of the objects and instrumentation during the implantation procedure.
Thus, there remains a need for further improvements in instruments and methods for minimally-invasive surgical techniques that aid the surgeon in positioning implants, devices and instrumentation at desired locations within the body of the patient.